EP0544051B1 - Supporting chain replacement - Google Patents

Abstract

In the cable guide, one or more ribbon cables (55) are laid in a duct (39) in parallel upper and lower layers (61, 57) joined by a reversal loop (55). The upper layer (61) is held down over part of its length by two mouldings (37) near the floor (45) of the duct. The end of the lower layer is fixed to a downturned foot (59) and the end of the upper layer to a sliding head (63) acting as a distance piece. In one extreme position (as depicted) the max. length of the upper layer is held down, leaving a min. length of the lower layer adjacent to the loop.

Description

The invention relates to a drag chain replacement for a line arrangement, the ends of which are connected to a fixed device or to a device movable relative thereto and which is flexible between the ends.

With such a drag chain replacement, for example, a reciprocating device can be connected to a fixed device.

Conventionally, drag chains or drag chain arrangements are used for this purpose, which have two or more chain belts made of metal or plastic, in which individual lines are guided. If the fixed device and the reciprocating device are arranged one above the other and the drag chains exceed a certain length with regard to the required movement path of the movable device, the upper run of the drag chain rests on its lower run. This either leads to a strong mechanical load on the drag chain or must be prevented by a false ceiling in the form of a sliding plate in a guide channel for the drag chain, the upper run of the drag chain being placed on the sliding plate. In addition, such a drag chain is expensive due to the high manufacturing and assembly costs, can cause considerable movement noises and, due to the play of the chain links relative to one another, enables longitudinal expansion, which is often undesirable.

In the own EP patent application 91105430.2 (EP-A-0490022) a drag chain replacement is described with which the problems of conventional drag chain arrangements are overcome. For this purpose, the line or line arrangement to be guided is provided, at least on the side on which the two runs of the line or line arrangement point to one another, with a sliding device which is effective in the longitudinal direction of the line and prevents friction between the two runs even when they are in contact. One of the possible solutions, which are specified in EP-A-0490022, consists in a line receiving channel in which one or more lines to be guided are arranged and which consists of material with good lubricity. Some of the embodiments for such a drag chain replacement shown in EP-A-0490022 are shown in the accompanying FIGS. 3, 5 and 6.

A further development of such a drag chain replacement in the form of a line receiving channel is described in its own EP-A-0544027. This further development consists in providing a wall of the line receiving channel with an insertion slot extending over its entire length, through which the line or lines which are to be received by the line receiving channel can be pressed into the line channel from the outside. An embodiment of this development is shown in the accompanying FIG. 4.

The embodiments of a drag chain replacement shown in the accompanying FIGS. 3, 4 and 6 are provided with transverse slots spaced apart in the longitudinal direction, which enable a loop-like bending of the drag chain replacement. The maximum bending radius is essentially determined by the spatial frequency, that is, the distance of the individual transverse slots from one another is determined.

The embodiments of a drag chain replacement shown in the accompanying FIGS. 3, 4 and 6 are very well suited for connecting a fixed and a movable device when the movable device moves back and forth linearly in such a way that the strands on both sides of the loop part are always accurate run parallel or one above the other and only be bent in one direction.

If a bend is also required in the opposite direction to that shown in the attached FIG. 6, it is possible to arrange oppositely directed transverse slots between the transverse slots shown. In the case of the line receiving duct shown in FIG. 3 for one or more loosely inserted lines, between the transverse slots penetrating from the upper channel wall, additional transverse slots penetrating from the lower channel wall would be arranged, each extending into the vicinity of the upper wall. Such a drag chain replacement would enable an S-shaped bending loop. However, such a drag chain replacement would allow pulling apart in the longitudinal direction, similar to a garland. This can be problematic, since the strain relief function of the line receiving channel for the inserted lines can then be lost and tensile stresses between the fixed device and the movable device can act on the lines guided with the drag chain replacement. From document D1 = US-A-3,630,325 a drag chain replacement for a line arrangement is known, the ends of which are connected to a fixed device or a device movable relative thereto, and which is flexible between the ends thereof. This known arrangement has in particular a line receiving channel 11, which has at least one channel interior for the loose reception of at least one line. Furthermore, this prior art shows a peripheral wall of the line receiving channel with a plurality of circumferential slots which are arranged at a distance from one another in the longitudinal channel direction and run transversely to the longitudinal channel direction and are interrupted by a web.

Neither conventional drag chains nor the previously described drag chain replacement embodiments enable three-dimensional mobility between fixed device and movable device. This is necessary, for example, if you want to connect a robot arm to a fixed device, for example at the base of the robot, and a plurality of joints which are movable in different directions are arranged between the robot arm and the fixed device.

With the present invention, a drag chain replacement is made available which allows three-dimensional movements of a movable device relative to a fixed device. This object is achieved by a drag chain replacement with the features specified in claim 1. Advantageous further developments can be found in the dependent claims 2-13.

For this purpose, the invention provides a drag chain replacement with a cable receiving channel, the outer circumferential wall of which is provided with a plurality of circumferential slots which are arranged at a distance from one another in the longitudinal channel direction and run transversely to the longitudinal channel direction and which, depending on the entire circumference of the cable receiving channel, run only around an articulated web or only is or are interrupted by two articulated webs diametrically opposite each other at an angular distance of 180 °. The webs of adjacent circumferential slots are offset from one another by a circumferential angle of 90 °. The width of the circumferential slots and their distances from one another are dimensioned in accordance with the desired maximum bending radius of the line receiving channel. The web width seen in the circumferential direction of the line receiving duct is only a fraction of the dimension of the associated duct wall in this circumferential direction.

In the case of a drag chain replacement that forms loop-like bending areas during operation and in which the runs located on both sides of the loop area can slide past one another, the width of the circumferential slots should not be made too large, to prevent the sliding strands from getting caught. In this case, a desired maximum bending radius should be made possible by a larger number of more closely spaced circumferential slots.

The maximum bending radius along the line receiving channel can be varied by making the distance between successive circumferential slots different in different channel sections.

With the same number of circumferential slots per unit length of the line receiving channel, a particularly high maximum bending radius is achieved by allowing each circumferential slot to run around the entire circumference of the line channel with the exception of a single articulated web. However, this can result in a certain longitudinal expansion in accordance with the garland effect. This embodiment is therefore not suitable if such longitudinal expansions of the line receiving channel are to be avoided. In this case, an embodiment is recommended in which each circumferential slot is interrupted by two articulated webs which are diametrically opposite at an angular distance of 180 °.

The thinner the webs seen in the circumferential slot direction, the greater is the bendability of the drag chain replacement and the less bending force has to be exerted in the case of a line receiving channel of predefined circumferential wall thickness and predefined material flexibility. However, there are limits to this due to the longitudinal tractive force that the drag chain replacement is intended to withstand. If you make the bars too thin, they can tear. Their thickness, viewed in the circumferential slot direction, is therefore preferably in the range from approximately 0.5 to 10%, particularly preferably approximately 2%, of the circumferential length of the line receiving channel.

The longitudinal directional stability of the line receiving channel and thus the drag chain replacement can be additionally increased by two dividing walls arranged crosswise in the line receiving channel, each extending from opposite points of the channel circumference and running in the longitudinal direction of the line receiving channel. Their intersection line of intersection is preferably in the neutral bending zone of the line receiving channel, in the case of line receiving channels with a symmetrical cross section, accordingly in the central longitudinal axis of the line receiving channel.

The line receiving channel preferably has a rectangular, circular, oval or elliptical cross section.

The circumferential slots continue from the circumference of the channel from the outer ends of one of the two partitions to the respectively opposite surfaces of the other partition, the partitions into which the circumferential slots extend alternate with respect to circumferential slots that follow one another in the longitudinal direction of the channel. As a result, the cross center of the two partitions remains uninterrupted over the entire length of the duct and can prevent the duct receiving duct from stretching longitudinally.

The invention provides a drag chain replacement with three-dimensional bendability, for which purpose a line receiving channel is provided which has circumferential slots spaced apart from one another in the longitudinal direction of the line, each of which runs except for a remainder in the form of one or diametrically opposite two webs. The webs of adjacent circumferential slots have an angular distance of 90 ° from one another.

Further embodiments can be found in the patent claims, which are hereby expressly made part of this description by reference.

Fig. 1

eine erste Ausführungsform eines erfindungsgemäßen dreidimensionalen, kanalförmigen Schleppkettenersatzes;

Fig. 2

eine zweite Ausführungsform eines erfindungsgemäßen dreidimensionalen, kanalförmigen Schleppkettenersatzes;

Fig. 3

eine Ausführungsform eines nur in einer Richtung verbiegbaren kanalförmigen Schleppkettenersatzes aus einer älteren EP-Anmeldung;

Fig. 4

eine Modifizierung der in Fig. 3 gezeigten Ausführungsform;

Fig. 5

eine Ausführungsform eines Schleppkettenersatzes mit Gleitbändern aus einer älteren EP-Anmeldung ; und

Fig. 6

eine Ausführungsform eines Schleppkettenersatzes aus einer älteren EP-Anmeldung mit Gleitrinnen.

Embodiments of the invention will now be explained in more detail with reference to the accompanying drawings. The drawings show:

Fig. 1

a first embodiment of a three-dimensional, channel-shaped drag chain replacement according to the invention;

Fig. 2

a second embodiment of a three-dimensional, channel-shaped drag chain replacement according to the invention;

Fig. 3

an embodiment of a channel-shaped drag chain replacement that can only be bent in one direction from an earlier EP application;

Fig. 4

a modification of the embodiment shown in Fig. 3;

Fig. 5

an embodiment of a drag chain replacement with sliding bands from an older EP application; and

Fig. 6

an embodiment of a drag chain replacement from an older EP application with slide channels.

1 shows a line receiving channel 11 for a three-dimensionally movable drag chain replacement. The line receiving channel 11 has a rectangular cross section and has an upper wall 13, a lower wall 15, a right side wall 17 and a left side wall 19. A vertical partition wall 21 extends in the middle between the side walls 17 and 19 from the upper wall 13 to the lower wall 15 A horizontal partition 23 extends in the middle between the top wall 13 and the bottom wall 15 from the right partition 17 to the left partition 19.

Terms such as left, right, vertical, horizontal, above and below are used for easier expression based on the illustration in FIG. 1. Of course, they do not apply absolutely, since a drag chain replacement, as shown in FIG. 1 and the other figures, can assume any positions other than those shown in the figures in practical use.

The entire line receiving channel 11 is preferably extruded in one piece. This includes the cross formed by the partitions 21 and 23 in the interior of the line receiving channel 11. The crossing point 25 runs in the longitudinal axis of the channel and thus in the neutral bending zone of the line receiving channel 11.

The line receiving channel 11 is provided with a plurality of circumferential slots 27 and 29, which are arranged at a distance from one another in the longitudinal direction of the channel and extend transversely to the longitudinal direction of the channel, each of which runs around the entire circumference of the line receiving channel 11 only of two articulated webs 31 that are diametrically opposite at an angle of 180 ° or 33 are interrupted. The webs 31, 33 are each in the middle of one of the side walls 17, 19 or in the middle of the upper wall 13 or the lower wall 15. The webs in the lower wall 15 and in the left side wall 19 cannot be seen in FIG. 1 .

In the embodiment shown, the webs 31 and 33 are formed by wall areas which have remained between the circumferential slots 27 and 29, respectively. The elastic and non-elastic bendability of the webs 31, 33 is therefore determined by the material used for the line receiving channel 11.

An essential aspect of the present invention is that the webs 31 and 33 of adjacent circumferential slots 27 and 29 are offset from one another by a circumferential angle of 90 °. This can also be expressed in a different way that the upper and lower regions of the circumferential slots 27 extend from the upper wall 13 and the lower wall 15 into the side walls 17 and 19, whereas the left and right regions of the circumferential slots 29 extend from the extend the left side wall 19 or the right side wall 17 into the upper wall 13 or the lower wall 15, each as far as the associated webs 31 and 33. The peripheral slots 27 extend from the peripheral ends of the vertical partition walls 21 to the opposite one Surface of the horizontal partition 23, while the peripheral slots 29 extend from the peripheral ends of the horizontal partition 23 to the opposite surfaces of the vertical partition 21. The crossing point 25 between the vertical partition 21 and the horizontal partition 23 therefore remains uninterrupted over the entire length of the line receiving channel.

Since a plastic material with a certain elastic bendability is used for such a line receiving channel 11, the webs 31 and 33 can perform a certain joint function. The webs 31 serve as joints for bending movements of the line receiving channel 11 in the direction of the vertical partition wall 21 upwards or downwards. The webs 33 serve as joints for bending movements of the line receiving channel 11 in the direction of the horizontal partition wall 23 to the left or to the right. The interaction of the joints formed by the webs 31 and by the webs 33 thus enables a three-dimensional movement overall. The maximum bending radius is due to the interaction of the circumferential slot width and spatial frequency, ie the number of circumferential slots 27, 29 per unit length of the line receiving channel 11.

Since each circumferential slot is interrupted by two opposing webs 31 and 33, and the circumferential slots 27, 29 do not extend through the crossing point 25, there is absolute longitudinal stability of the line receiving channel 11 against longitudinal expansions.

This longitudinal stability is also maintained if only one web 31 or 33 is provided on the outer circumference of the line receiving channel 11 per circumferential slot 27, 29 and the respective circumferential slot 27 or 29 the partition 21 or 23 not adjoining the web 31 or 33 from their two circumferential ends to the intersection 25 and the partition 23 or 21 adjacent to the web 31 or 33 only penetrates from the circumferential end distant from the web 31 or 33 to the intersection 25, the intersection 25 itself everywhere remains inseparable.

If the longitudinal expansion is not a problem or is even desired, only one web 31 or 33 is seen per circumferential slot 27, 29 and either leaves the partitions 21, 23 completely away or sets each circumferential slot 27, 29 through both partitions 21, 23 through that nothing remains except the one web 31 or 33. In these two cases, a garland-like pulling apart of the line receiving channel 11 is possible.

The width of the webs 31, 33 in the direction of the circulation slots 27, 29 is mainly determined by the desired bendability of the line receiving channel 11 and thus depends on the one hand on the elasticity of the for the line receiving channel 11 selected material and on the other hand from its wall thickness.

Through the partitions 21 and 23, four inner chambers 35 are formed in the interior of the line receiving channel 11, into each of which one or more single or multi-core lines can be inserted. This division has the advantage that the individual lines do not move back and forth so far in the radial direction during a bending movement of the line receiving channel 11.

If strong bending movements of the line receiving channel 11 are made possible and required, it may be advantageous to build up the lines inserted into the line receiving channel 11 with memory-capable material and to pre-shape them into a spiral shape by means of memory treatment, as is known from telephone handset lines. The lines can then easily undergo expansions which are caused by a strong bend in the line receiving channel and can be reversed from this strong bend after the line receiving channel 11 returns.

FIG. 2 shows an embodiment which corresponds to the embodiment according to FIG. 1, with the exception of T-shaped slot widenings of the circumferential slots 27 and 29. The slot widenings can also have another shape, for example circular or elliptical. The slot widenings 37 on the one hand prevent the risk of tearing the slot ends of the circumferential slots 27 and 29. The slot widenings 37 on the other hand result in an increase in the web lengths of the webs 31 and 33 in the direction transverse to the direction of the circumferential slots 27 and 29, which results in the elastic bendability of the webs 31 and 33 increased.

3 to 6 show drag chain replacement embodiments for a better understanding of the invention, which are already shown in the aforementioned (post-published) patent applications EP 91105430.2 and EP 91120167.1. A detailed description in the present application is therefore not necessary. For this, reference is made to the aforementioned EP patent applications. 3 to 6 each show an embodiment of a drag chain replacement that is only bendable in one direction. In the case of FIGS. 3 and 4, the drag chain replacement is formed by a line receiving channel 39 with transverse slots 41 introduced from the top (seen in FIGS. 3 and 4). In the embodiment shown in FIG. 4, the upper wall is also provided with a longitudinal gap which extends in the longitudinal direction of the channel and through which lines 45 can be pressed into the interior of this line receiving channel.

Fig. 5 shows a ribbon line 47, which is bent like a loop to an upper run and a lower run, the sides of which face each other are provided on their side edges with a sliding band 49 each made of material with good sliding properties.

Fig. 6 shows an embodiment of a drag chain replacement with two ribbon cables 47, the side edges of which are each inserted into a slide channel 51 made of material with good sliding ability. The slide channels 51 are provided with transverse slots 41, through which they can be bent together with the ribbon cables 47 in the manner shown in FIG. 6. By means of transversely extending retaining clips 53, the two ribbon cables 47 and the associated slide channels 51 are combined to form a drag chain replacement line unit.

According to the second aspect of the invention, the line receiving channels 39 in FIGS. 3 and 4, the slide bands 49 in FIG. 5 and the slide channels 51 in FIG. 6 are constructed with memory material, by means of which they each store a preferred form, that of a preferred position, in particular neutral position or rest position, an associated movable device is adapted.

In the embodiments shown in FIGS. 5 and 6, the memory effect can also be generated or also generated by constructing the ribbon line or ribbon lines 47 with a material having a memory effect.

Claims (13)

1. A dragchain replacement for a line assembly whose ends are connected to a stationary means and to a means movable relatively thereto, respectively, and which is flexible between its ends, wherein

   a) the dragchain replacement comprises a line receiving channel (11) having at least one channel interior space for loosely accommodating at least one single- or multi-conductor line,

   b) the circumferential wall of the line receiving channel (11), for bendability of the line receiving channel (11) transversely of its longitudinal direction, is provided with a multiplicity of circumferential slots (27, 29) spaced apart in the longitudinal direction of the channel and extending transversely of the longitudinal direction of the channel, with each of said circumferential slots, in extending around the entire circumference of line receiving channel (11), being interrupted only by one web (31, 33) with articulation effect or only by two webs (31, 33) with articulation effect located diametrically opposite each other with an angular spacing of 180°,

   c) and with the width of the circumferential slots (27, 29) and the distances from each other being dimensioned in accordance with the desired maximum bending radius of the line receiving channel (11),
   characterized in

   d) that the webs (31, 33) of adjacent circumferential slots (27, 29) are offset from each other by a circumferential angle of 90°,

   e) with the web width as seen in circumferential direction of the line receiving channel (11) being only a fraction of the dimension of the associated channel wall in this circumferential direction.
2. A dragchain replacement according to claim 1, characterized in that the line receiving channel (11) consists of a material with good slidability on itself or is provided with such material on at least one outer wall.
3. A dragchain replacement according to claim 1 or 2, characterized in that each web (31, 33) as seen in the circumferential direction of the line receiving channel (11) has a web width in the range from about 0.5 to 10 %, preferably of about 2 %, of the circumferential length of the line receiving channel (11).
4. A dragchain replacement according to any one of claims 1 to 3,
   characterized in that the distance between adjacent circumferential slots (27, 29) in the longitudinal direction of the line receiving channel (11) is the same throughout the length of the line receiving channel (11).
5. A dragchain replacement according to any one of claims 1 to 3,
   characterized in that the distance between adjacent circumferential slots (27, 29) in the longitudinal direction of the line receiving channel (11) is different in various sections in longitudinal direction of the line receiving channel (11).
6. A dragchain replacement according to any one of claims 1 to 5,
   characterized in that the circumferential slots (27, 29), at their ends adjacent the webs (31, 33), are provided with slot ends (37) expanding preferably in T-shaped, elliptical, oval or circular manner.
7. A dragchain replacement according to any one of claims 1 to 6,
      characterized in

   - that the line receiving channel (11) is subdivided by at least two partitions (21, 23) into a plurality of inner chambers (35) extending in longitudinal direction of the channel, with said partitions (21, 23) crossing (25) each other in the neutral bending zone formed preferably by the longitudinal axis of the line receiving channel (11), and extending between opposite circumferential locations of the line receiving channel (11),

   - that each circumferential slot (27, 29) continues from opposite circumferential ends of one of the two partitions (21, 23) up to the intersection (25) of the partitions (21, 23) without extending through said intersection (25),

   - that each circumferential slot (27, 29) is interrupted by two webs (31, 33) of the circumferential wall of the line receiving channel (11) which are located opposite each other with a circumferential angular spacing of about 180°, with said webs (31, 33) each being adjacent a circumferential end of a partition (21, 23) through which no circumferential slot (27, 29) extends,

   - and in that successive circumferential slots (27, 29) in the longitudinal direction of the channel continue in alternating manner in different partitions (21, 23).
8. A dragchain replacement according to any one of claims 1 to 6, characterized in

   - that the line receiving channel (11) is subdivided by at least two partitions (21, 23) into a plurality of inner chambers (35) extending in longitudinal direction of the channel, with said partitions (21, 23) crossing (25) each other in the neutral bending zone formed preferably by the longitudinal axis of the line receiving channel (11), and extending between opposite circumferential locations of the line receiving channel (11),

   - that only one web (31, 33) is provided for each circumferential slot (27, 39),

   - that each circumferential slot (27, 29) extends through the partition (27, 29) not adjoining the web (31, 33) from the two circumferential ends of said partition up to the intersection (25) and through the partition (27, 29) adjoining the web (31, 33) only from the circumferential end remote from said web (31, 33) up to the intersection (25), with the intersection (25) proper remaining unseparated at all locations,

   - and that, with successive circumferential slots (27, 29) in the longitudinal direction of the channel, the partitions (21, 23), having the particular circumferential slot (27, 29) extend therethrough from both circumferential ends and the partitions (21, 23) having the particular circumferential slot (27, 29) extend therethrough from only one circumferential end, alternate with each other.
9. A dragchain replacement according to any one of claims 1 to 6,
      characterized in

   - that the line receiving channel (11) is subdivided by at least two partitions (21, 23) into a plurality of inner chambers (35) extending in longitudinal direction of the channel, with the partitions (21, 23) crossing (25) each other in the neutral bending zone formed preferably by the longitudinal axis of the line receiving channel (11), and extending between opposite circumferential locations of the line receiving channel (11),

   - that only one web (31, 33) is provided for each circumferential slot (27, 29),

   - and in that each circumferential slot (27, 29) extends completely through both partitions (21, 23) and thus also through the intersection (25) thereof.
10. A dragchain replacement according to any one of claims 1 to 9,
    characterized in that the line receiving channel (11) has a closed rectangular cross-section.
11. A dragchain replacement according to any one of claims 1 to 9,
    characterized in that the line receiving channel has a closed circular, elliptical or oval cross-section.
12. A line assembly comprising a dragchain replacement according to any one of claims 1 to 11 and comprising at least one single- or multi-conductor line (45) arranged in the dragchain replacement.
13. A line assembly according to claim 12,
    characterized by a dragchain replacement according to any one of claims 1 to 11, comprising a line receiving channel (11), and by at least one single- or multi-conductor line that is loosely inserted in the line receiving channel (11; 39) and is composed with a material having a memory effect and is preformed in a helical shape.

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